A weblog for professionals in electrical, electronic, mechanical and software engineering with content provided by the members of the Long Island Consultant's Network.

August 2012

August 30, 2012

Trolley cars in New York City are a thing of the long past. At one time though, trolleys were all over the place and the streets were crisscrossed with their tracks. Eventually though, buses replaced the trolleys and New York City had to do something about all of that idled trackwork.

In many places, road crews tried to simply bury the tracks under layers of new asphalt. That was supposed to be a cost savings measure versus having to actually remove the tracks themselves, but it didn't work. Old track rails kept surfacing as their asphalt layers broke down over the course of time. Eventually, track removal had to be undertaken.

August 28, 2012

As a small child, I wondered why anybody would go the trouble of making trees out of wood. I thought it would be more sensible to just make tables and chairs and bookcases and skip the intermediate step.

I first wondered about this question when my folks took me and my little sister on a walk through Kew Gardens and we saw all these stately Sycamores everyplace over there. Just to mention by the way, that was Kew Gardens in the borough of Queens in New York City, not the Kew Gardens in Great Britain.

I also once wondered how the clutch on a stick-shift automobile worked. I envisioned hands emerging from the four tire treads trying to grab and hold on to the pavement whenever we came to a stop.

I once wondered if the entire world was encased in concrete and asphalt. It seemed to be the case in my neighborhood, so was that true everywhere? That didn't seem to me like it would be a good thing.

August 25, 2012

We have a serious drought in the U.S., but I don't have a good understanding of the North American monsoon wind patterns. There is also serious drought on the the entire Indian Subcontinent and the Indian summer monsoon is simpler to describe. When Spring arrives, the land heats up, heating the air above it. This air rises and is replaced by air that comes in from the Arabian Sea which lies to the west of the Indian peninsula. This air contains moisture that evaporates from the water. The Western Ghats mountain range runs along the western edge of the Indian peninsula and the incoming air must rise up to cross the mountains. This air encounters lower pressure at the higher altitude, so it expands, cools adiabatically, and if it cools down to the dew point, moisture condenses out on cloud condensation nuclei (CCN). CCN are aerosol particles which can be dust particles, sea salt crystals, organic matter, soot, etc. If the water droplets are large enough, they may coalesce and form droplets that are heavy enough to precipitate. My understanding of cloud physics is deficient, so I will oversimplify the reason why the Indian summer monsoon has not produced sufficient rain: too little moisture distributed on too many CCN. The drought is not only on the coast. The winds flow over the entire subcontinent, reaching the Himalayas.

August 21, 2012

Stories of mis-delivered mail are commonplace, but this letter takes the cake. It was mis-delivered twice.

The lettering "DELIVERED TO INCORRECT RESIDENCE - PLEASE RE-DELIVER" is not in my hand. Somebody else wrote that which means that this letter got delivered to some other wrong address before it showed up in my mother-in-law's mail slot. Her address is similar to the one shown.

I added the word "TWICE" and I added the underlines and the exclamation marks. I was about to re-mail it when I had a change of mind. Instead of re-mailing, I looked up and telephoned the Fishman family.

Mrs. Fishman was delighted to hear from me and asked me to open the letter for her.

August 18, 2012

These three abbreviation stand for Kilowatt-hour, Megawatt-hour and Gigawatt- hour. They are measures of energy and are related to each by 1000 i.e. Megawatt is 1000 times a Kilowatt and a Gigawatt is 1000 times a Megawatt.

When we talk about the energy in say an EV or a home Kilowatt-hour is convenient. When we speak about peaking generators, the Megawatt-hour is convenient. When you start speaking about a state or a collection of states then the Gigawatt-hour is needed.

For example an EV such as the Nissan Leaf has a battery capacity of 23 Kwh and a range of 70 to 100 miles depending upon how you drive it. My home has a 200 amp service, hence can draw up to 200 x 240= 48,000 wh or 48 Kwh. Now that is a maxed out case but Kwh fits for comparison.

August 16, 2012

In and around the metropolitan area, every day, I see numerous drivers commit moving violations, some of astonishing risk to themselves as well as to others. Often, the drivers of those vehicles have taken steps to prevent anyone from reading their license plate numbers. Here are three such examples.

Example 1: The license plate is encased in an obscuring plastic holder.

August 11, 2012

The ancient Greeks had sophisticated metalworking technology. There was even Hephaistos, the Olympian god of sculpture, fire, stonemasonry and metalworking. Also, they knew about magnetism via lodestones. In theory at least, they had the resources in ancient times to develop electromagnetic technology. Just imagine what the world's history would have been if they had done so!

Thomas Edison noticed that his light bulb had some unexpected operational side effects, one of which was that a metal plate placed inside the glass envelope could carry current in one direction in a set-up as sketched below. He observed the effect, even though he wasn't the first person to have seen it happen. However, he couldn't explain it and so he abandoned the phenomenon. He just never got around to putting another element, a grid, between those first two items to see what would happen next. Just imagine what the electronics industry's history would have been if he had done so!